Cardan joint type monobloc couplings, obtained from a single sheet element, are well-known, such as the one described in the French patent No. 1 515 051.
The French patent No. 2 458 002 on behalf of the Applicant relates to a cardan joint obtained from a sheet blank. It exhibits an open hub with reinforced holes for letting its fastening means through. This type of coupling does not allow absorbing the relatively important stresses which may take place in certain applications.
The French patent No. 2 448 068 relates to a cardan joint, produced by cutting and cold-rolling of a sheet blank, and includes a jaw formed by two legs attached to a split hub. According to this document, the split hub exhibits two longitudinal rims which must be rigorously opposite one another, so that their profiles may penetrate into one another in order to sustain stresses liable to distort this hub. As the hub is relatively compact and as longitudinal rims must face each other, specific disengagement means call for a delicate manufacture and a random quality level. These performance problems cause an increase in cost and a quality level which is not constant, which is particularly disturbing for mass-production in the automotive industry.